That headline certainly caught my attention to. It comes from this Toronto Sun article about Gretz promoting his new series of wines at liquor store in Summerhill.
"A white cabinet next to the paper towel dispenser has been defaced with a blue Sharpie: “Thanks for a Great Day! Your Friend Wayne Gretzky 99, Dec 2010”
“We have a book that celebrities usually sign,” Bailey said. “This is the first time anyone has signed the bathroom wall.”
Here's the full article.